摘要
采用海藻酸钙凝胶将低浓度的休哈塔假丝酵母（Ｃａｎｄｉｄａｓｈｅｈａｔａｅ）细胞包埋固定后，进一步通过增殖培养，使细胞密集在凝胶珠的表层，可以减小营养基质、氧气及发酵产物的传递阻力，有利于该菌的“半好气”酒精发酵。试验中发现，在凝胶中掺入适量氧化铝能明显增加固定化小珠的机械强度及使用寿命。固定化休哈塔假丝酵母细胞能够利用己糖和戊糖，８０ｇ／Ｌ的混合糖（己糖与戊糖１：ｌ）经１２ｈ发酵，糖的利用率达９０．５％，而相同条件下游离细胞发酵需４８ｈ。玉米秆经０．７５％Ｈ＿２ＳＯ＿４预水解后，在纤维素酶作用下进一步水解。利用固定化休哈塔假丝酵母细胞，可以将玉米秆水解液中的己糖和戊糖成功地发酵成酒精，塘的利用率达９２％，酒精得率超过理论值的９０％，显示了良好的应用前景。
Experiments of cell immobilization of Candida shehatae R,and fermentation of corn stalk hy-drolysate by the immobilized cells are reported.By entrapping a small number of cells into calcium alginategel beads and further incubation of the beads under suitable conditions for cell growth,the cells of Candidashehatae R were densely immobilized on the periphery of the gel beads,thus reduced the internal diffusionlimitation and created favourable environment for semiaerobic fermentation of Candida shehatae,It wasfound that addition of alurninum oxide into alginate gel could improve the mechanical strength and perma-nence of the beads obviously.The immobilized cells could utilize both hexoses and pentoses, 90.5%sugarin 80 g/Lsugar solution(glucose to xylose,1 :1)was utilized after 12 h fermentation,while 48 h were re-quired by free cell fermentation of the same medium。 The hydrolysate,which contains pentoses and hexosesproduced by pretreatment of corn stalk with 0.75%H_2SO_4 and further hydrolized by cellulase, could befermented to ethanol effectively by the immobilized cells The sugar utilization efficiency was over 92%,and the ethanol yield was higher than 90%of the theoretical. The results have shown broad prospects ofappllcatlons.
出处
《林产化学与工业》
EI
CAS
CSCD
北大核心
1994年第1期51-55,共5页
Chemistry and Industry of Forest Products
基金
南京林业大学自然科学基金
关键词
固定化细胞
发酵
玉米秆
水解液
Immobilized cells
Fermentation
Pentose
Corn stalk hydrolysate
Ethanol
